1. Field of the Invention
The present invention generally relates to a cassette and tray system wherein cassettes of varying sizes are used to hold collections of orthodontic or dental tools for use in the sterilization process.
2. Background Information
While the human mouth is hardly a sterile environment, there is a need to protect patients from the transmission of infectious diseases from one patient to another through the use of contaminated orthodontic or dental tools. Gone are the days when the orthodontist or dentist merely washed his hand tools between use on patients. Such organizations as the American Dental Association, American Association of Orthodontics, the Federal Occupational Safety and Health Administration and the Center for Disease Control are all actively working to set standards and guidelines to insure the safety of the patients as well as the orthodontists, dentists, and their assistants.
At the present time, there are three standardized methods of sterilizing dental and orthodontic hand tools. In each of the three, the hand tools are first dropped into a tank containing water and perhaps solvents, and ultrasound is applied to agitate the fluid to wash and remove the debris remaining on the hand tools from their last use. The tools are left somewhat damp then dried and heated in some manner to a temperature sufficient to destroy any microorganisms or viruses on the hand tools. The three primary methods of doing this are the use of dry heat, heat wherein the hand tools are heated to a temperature of at least 365xc2x0 Fahrenheit for six minutes, or the use of steam under pressure in an autoclave system. The time to sterilize, using a steam autoclave system, depends on heat and pressure and whether the instruments are wrapped or not. A common wrapped cycle is 270* at 27 psi for fifteen minutes. An unwrapped cycle at the same temperature and pressure would be for three minutes. In some sterilization processes, chemicals are applied to the hand tools as an intermediate step between the ultrasonic bath and the heating. A third method of sterilization is a chemical clave wherein a heated, controlled atmosphere of various gases is used to heat the hand tools held within sealed sterile paper bags.
The problem is that orthodontists and dentists with busy professional practices will see many patients in any given work day, indeed it is not unusual for an orthodontist to see in excess of 100 patients per day. A lot of hand tools are used each day, and they are generally collected throughout the day and recycled, in bulk, through the sterilization process. In a busy orthodontics practice, it is not unusual to have one assistant dedicated solely to collecting hand tools and sterilizing them on a full time basis.
In the typical prior art orthodontic or dental practice, once the tools have been resterilized, they are simply returned to the work station and placed where they are readily available for reuse. However, this is a source of contamination. If, for example, a dentist is working on a patient""s teeth and calls to his assistant for a new and different tool, and the assistant reaches into the drawer to retrieve the tool wearing a latex glove that has been contaminated with the body fluids of the patient, the assistant can transfer those contaminants to other, unused tools which were previously sterilized. Inevitably, conditions arise where contaminated hands are used to retrieve tools from the drawers.
Accordingly, what is needed is a cassette system wherein cassettes can be preloaded with standard sets of tools for use in either orthodontic or dental practices, and kept together as a set throughout the sterilization process. What is also needed is a means of collecting the cassettes into convenient packages where they can be batch fed through the ultrasonic bath and heat applications, and remain in a sterile condition when they are returned as a set to the work station. Additionally, this cassette collection system must require a minimum amount of counter space at the vicinity of the dental chair, either on the bracket table or the work side unit, and finally, the cassettes must be configured such that they remain stable and flat on the countertop surface when opened so that they do not fall off the table onto the floor, or worse yet, the patient.
These are the objects of the present invention.
Additional objects, advantages and novel features of the invention will be set forth in part in the description as follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
These objects are achieved through use of a transport rack and a plurality of cassette systems. The transport rack is formed of side walls, a back wall, and a bottom wall which are all interconnected to form a rigid transport rack. The tray is provided with a plurality of shelves for holding cassettes which are inserted through the front of the transport rack. The walls and shelves of the transport rack are provided with a plurality of holes or slots through which fluids and debris cleaned during the ultrasonic cleaning portion of the sterilization process may readily pass.
The transport rack is also provided with two flanges which are attached to the top of the side walls. The transport rack is dimensionally sized to a preselected dimension as to provide for interchangeability of cassettes as is later described.
There are two basic designs for the cassettes. In the first design, first and second hinges are provided, with the first interconnecting the side wall of the cassette to a hinge plate, and the second hinge interconnecting the hinge plate to the top cover in such a manner that when the top cover is opened, it may be levered open from the top edge of the back wall and the hinge plates swinging down such that the cover lies flat against the surface upon which the cassette is resting. Like the transport rack, slots or holes are provided to allow for the passage of fluid and debris out from the cassette.
In the second design for the cassettes, the top cover is divided into two portions, the first being the cover portion and the second being the hinge plate with the hinge plate attached to the top of the side wall and the second hinge interconnecting the hinge plate to the remainder of the cover. As in the first design, the double hinge arrangement allows for the cover to be opened and laid flat against the surface upon which the cassette is resting.
In a third design, a fold down plier rack is provided, which can be tilted up and used to hold pliers in a generally vertical orientation wherein the do not become entangled with each other.
In all designs, two opposing latch assemblies are provided so that equal and opposite pressure must be applied to the latches in order to unlatch the top cover so as to open it. The purpose of providing the double latches and the requirement for equal and opposite pressure is to prevent inadvertently pushing the transport rack off of the surface upon which it is resting since the use of both hands is required to open the latches.
The cassettes are sized in plurality of different sizes with the largest size and all intermediate sizes being full integer multiples of the smallest cassette size such that if the cassettes are used in a random manner, they can still be conveniently stacked to fully pack a transport rack prior to the sterilization process.
The cassettes are also provided with color coded buttons fixed to the end walls so that the kits of dental tools that are contained within each cassette can be readily identified.
Two types of handles are provided, the first being a top handle which is provided with a pair of opposing plates which interfit underneath the flanges attached to the tops of the side walls along with a locking or insertion button to prevent the tray from sliding off of the handle plates. A side, levered handle is also provided with two insertion plates which also insert underneath and interfit underneath the flanges to permit withdrawal of the cassette from a sterilization device, which may be hot, having only a side wall opening.
Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description wherein I have shown and described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated by carrying out my invention. As will be realized, the invention is capable of modification in various obvious respects all without departing from the invention. Accordingly, the drawings and description of the preferred embodiment are to be regarded as illustrative in nature, and not as restrictive.